US2664237A - Paper container - Google Patents

Description

Dec. 29, 1953 R. s. SANFORD 2,664,237

' PAPER CONTAINER Filed Nov. 4, 1947 2 Sheets-Sheet l INVENTOR S. Sanford.

BY MW 1 ATTORNEYS Dec. 29, 1953 5, SANFORD 2,664,237

PAPER CONTAINER Filed Nov. 4, 1947 2 Sheets-Sheet 2 INVENTOR Roy S.Sa1 zford.

Patented Dec. 29, 1953 gram orrlce PAPER CONTAINER .Roy S. Sanford, Oakville, Conn assignor, by mesne assignments, of one-half to Ex-Cell-O Corporation, Detroit, Mich., a corporation of Michigan, and one-half to a group comprising Ace C. Fessenden, Chicago, llL, andAoe Carton Corporation, Chicago, 111., a corporation of Illinois Application November 4,1947, Serial No; "183,904

1 Thisinvention relates to containers of paperboard or other sheet material, and more particularly to a novel liquid-tight and sift-proof'container and to a means andmethod for making the same.

One of the objects of'thepresentflmvention is to provide a novel papercontainer blank which is readily adapted for quick and efllcient'sealing at both ends, the construction being such that complete sealing of all pin holes and cracks is:

achieved, thus providing a container having end portlonswhich are completely air-tight, when used for liquids, or sift-proof when employed for powdered materials.

Another object is to provide a closure for the upper end of a tubular container, so constituted as to permit portions of the cont iner forming the end closure to be adhesively bonded together at a relatively high pressure suflicient to effect a positive flow of adhesive between the portions to fill and seal all cracks and openings therebetween at the container end.

A further objectis to provide a novel closure for the upper end of a container of the above type, so constituted as to facilitate the filling of' the container and the subsequent sealing of the end thereof.

Still another object is to provide'a container of the above type having separate dispensing and filling openings so arranged as to facilitate the ffilling'of'the container andthe subsequent dispensing of the material therein. 7,

Yetanother object is to provide "a container of neTa'bovetype'ha-Ving separate'filling and dis- 4, V sensing 'openingsand closure means therefor, and

'so' constituted as. to ,permitclosingand sealing "of the :dispensing" opening prior to filling of the container, and .subsequentsealingpf the filling opening, thns providing I a container :having a "sanitary dispensing opening which remains sealed not "only.duringilthefilling. operation'but .until the dispensing opening isuncoveredto dispense' the contents of the :container.

A iurther'object-is to'provide a sanitaryliquidtight "and sift:proof container having. separate dispensing and'filling openings :and iormedfrom a single piece of sheet .materialsuchas :paperboard. 1

Another object'isto provide a cohtainerofithe above :typehaving 'filling'opening adapted'tm,

nether object; "of the inventionfis :to pro- .9 Claims. (CL. 22937) A. furtherobject of the invention is to provide a means andmethod ofefiecting initial temporary and subsequent final sealing of a closure member on a container so constituted as to permit the temporary seal to be broken without damage to the container and to permit/a permanent final seal to. be effected thereafter.

'Yet-anotherobject is to provide a blank for a container of the'above' type having a closure flap for'a fillingopening hingedly secured to a portion of the blank and secured to but readily detachable from another portion of the blank to permit handling "of the blank without damage to said flap.

,A'still further object is to provide a container having "separatefilling and dispensing openings and closure means for the filling opening so con- 'parafiin or other thermoplastic material and a heat-sea1able end closure, 9, novel means and method for substantially preventing said coating from melting and dropping into the interior of the containerduring the heat-sealing operation.

Another object is to provide, in connection with a container of the type having separately operable and hingedly connected dispensing and filling 'flaps, means for separately sealing said flaps and for insuring a seal along the hinge line therebetween.

Other objects andnovel features of the invention will appear more fully hereinafter from the following detailed description when considered in connection with the accompanying drawings, wherein one embodiment of the invention is illustrated. It is to be expressly understood, however, that the drawings are utilized for purposes of illustration only, and'are not to be taken as a definition of the limits of the invention, reference being had for this purpose to theaccom- "panying claims.

In the drawings, wherein similar reference characters refer to similar parts throughout the several views:

Fig. l is'a plan view of a' blank adapted to be formed intothe novel container of the present invention;

sleigh ,2 is perspective viewoof, a partiallyas- .,-.-sembled container and x methanism, foriforming the container;

3 is a perspective view showing a step in formation of the end closure and mechanism forming the end closure;

- ig. is a perspective view of a container with the end closure partially completed;

Fig. 5 is a perspective View showing another step in the formation of the end closure and mechanism for formin. the end closure;

Fig. 6 is a perspective view of the upper end of a container showing a completed end closure, and

7 is a pers ective view showing the mechanism of Fig. 5 in more complete detail.

The present invention is particularly directed to a means and method for forming and sealing a container of sheet material, the bottom end of the container being preferably closed and sealed as set forth more fully in the copending application of Roy S. Sanford and Wilfred A. Eaton, Serial No. 644,547 filed January 31, 1946, now Patent No. 2,596,224, for Paper Container, owned by the same assignee as the present application. The up er end of the container is in general preferably formed as set forth in the copending applications of Wilfred A. Eaton, Serial No. 671,832, filed May 23, 1946, now Patent No. 2,596,225, for Paper Container, and Roger H. Casler, Serial No. 699,750, filed September 27, 1946, now Patent No. 2,581,237, for Dispensing Containers likewise owned by the same assignee as the present application, the instant application setting forth certain improvements in struc tures of the above type, as will be more fully described hereinafter.

Containers of the type shown and described in the instant application and in the above referred to applications are ordinarily formed and filled by means of automatic machines, and when such containers are used for mill: and similar products, it has been found desirable for sanitary reasons, to separate as completely as possible, the operations of forming the container from the operation of filling the container. Such a result can be obtained by forming the container in one room and filling and closing the container in an entirely separate room, the formed containers being transported to the filling room by suitable oonveyor means which may be so constructed as to conform with sanitary requirements. As will be shown, the container of the present application is particularly adapted to meet these requirements, as the container may be substantially completed before being filled, the only operations required after filling being those of closing and sealing a filling flap.

It is likewise desirable in some cases to form the containers and ship them empty to another place for filling, in which case they must be sealed during shipment to prevent contamina tion of the interior, and subsequently opened, filled, and rescaled. The present invention provides for this contingency, in that the container may be formed and temporarily sealed at one place, and thereafter opened without damage to the container, filled, and permanently sealed at another place, ready for distribution to the customer, it being noted in this connection that the dispensing opening, which is closed when the container is formed, is not disturbed in any way during the subsequent opening, filling and re sealing operation, and consequently is not sub ject to contamination before reaching the consumer.

Referring more particularly to Fig. l, the present invention is illustrated therein as including a container blank divided by scored folding lines 5 into preferably rectangular wall panels 5,

' panel s, which may be provided with a coatir" of the half-flaps being folded 4, E, 8, and S, the panel 5 being provided with a glue flap it adapted to be adhesively secured to adhesive 5 i along the lower edge thereof for purpose. As set forth the copending app tion of Roy S. Sanford and Wilfred A. Eaton. above referred to, the wall panels 6 and :i provided at their left ends with integral halfflaps I 2 and l3, .vhile the panels l s are provided with full flaps i l and the f 5 i2, and it, i5, 'thus being in opposed 'wationship when the container is assembled. Flaps 53 are provided with scored lines it l? which divide the half flaps into separate p els of the same shape and substantially eque ea, the inner surfaces of flaps l2 and 53 having a coating 88 of a flowable adhesive. The inner surface of flap I5 is provided with a similar adhesive coating it and the flap id is provided with narrow strips of adhesive coating 2%. The blank is formed into a tube and the bottom closed and sealed as described in the above refer ed to application of Sanford and Eaton, the in panels together and in side of the container with their adhesively coated surfaces together and the flaps It and iii being folded thereover and subjected to pressure to bond all of the flaps together and to force adhesive outwardly between the two panels of the half flaps toward the side walls and corners of the container to seal all openings therebetiveen.

Referring to the ri ht hand portion of Fig. l, a score line 2! defines, in cooperation with angularly disposed score lines 22, 25, 2% and 25, substantially isosceles trapezoidal shaped panels 25 and 21, and adjacent substantially triangular panels 28. Additional score lines 28a. and and a partially out line 3% define, in conjunction with score lines 5 and 2!, rectangular panels 3i and 32. Other angularly disposed score lines and 35 define, in connection with score lines 5, 2 i and a score line 3?, isosceles trapezoidal panels 35 and adjacent triangular panels 39, while the score lines 5, 2i, and 3's define a pair of rectangular panels 350:.

Top closure flaps and 4! are provided, and are preferably formed integral with and adjacent to panels 3i and 32 respectively, and hingedly secured thereto along score lines 28a and 29. The flap 4i] has an opening 42 provided with a dispensing portion or opening 43 and a preferably enlarged filling portion or opening M. While the openings s3 and 44 form portions of a single opening 32 in the form illustrated, it will be understood that if desired, the openings 43 and 44 may be separately formed in the flap 4B, in which event, a narrow Web or bridge may separate the two openings. The outer closure flap ll is adapted when folded to overlie and close the opening 42, and is provided with a tear strip or dispensing port forming member 45 separable from the flap M as along perforations 46, and adapted to cover the dispensing portion 43 of opening 32 when the flap 4! is in closed position. The separable member is preferably provided with an opening tab 4'! extending therefrom, and having scored folding lines 48 and 49 dividing the tab into portions 50 and 5|. A score line 52 is provided substantially along the median line of flap 4|, thus dividing the latter into integral and hingedly connected portions 53 and 54. The portion 54 is separated from panel 32 by the cut line 30, but in order to facilitate handling the blank, a small piece of paper 55 is left uncut to provide a separable conher will receive a coating of the protective material, thus insuring that the portions thereof which are exposed to the container contents are pro vided with a sanitary protec ve coating. In the event no adhesive is applied to the under surface of the tear strip 45, the coating material tends to fill seal any openings between this strip and the flap it, thus insuring a lealzproof closure at this point, as well as a protective coating of the outer surf cc of flap adjacent the inner surface of the tear strip l and around the dispensing port.

The container is now ready for filling, and may be filled with a product such as milk, for example, either manually or by suitable automatic machinery, shown, thereafter closed and. sealed for ery to the consumer. During the the hop lid is held in upwardly extending position by sutable means, not shown, thus permitting filling of the container through the opening When the container is to be filled with food products, and particularly with fluid milk, it important for sanitary reasons that no mill: be allowed to collect on the outer surface of the dispensing closure flap l: and adjacent areas, and particularly adjacent the strip and the perfora ions 55. The upwardly extending flap performs an important function in this connection, in that it provides an effective shield between the filling opening and the outer surface of flap 53 to prevent splashing of liquid on the latter from the region of the filling opening during the filling operation.

The final closing and scaling is accomplished by folding the flap 5t downwardly against flap all to cover opening 44, and placing the upper end of the container on a suitable machine 75, shown in Fig. 7, to effect sealing of the closure flap. The machine '15 may be provided with a U -shaped lower die it adapted to receive the upper end of the container and to support the flange forming panels 2%, 2i and and a similarly shaped upper die 7'! movable by suitable means vertically with respect to the die it. With the flap 54 folded to closing position, the top of the corn tainer is moved into the die it with the flap 56 toward the rear and the tab ill at the front of the container as shown in Fig. 5, whereupon the die if is moved downwardly to force the flap 54 against the upper surface of flap it to effect a bond and seal therebetween. In the event the adhesive utilized is of a heat-sealing type, a heating element it; may be provided in the die Ti. If found desirable, a similar heater, not shown, may be provided for the lower die it. In order to insure complete sealing of the flap at to flap it, the dies are so arranged as to apply pressure across and on both sides of the hinge score line 52. It is also to be understood that these dies, as well as the slides and plunger of machine 63, are so contoured as to compensate for the number of layers of paperboard material being bonded in different areas, in order to insure adequate bonding pressures between all surfaces. Since the portion of ll has previously been bonded to flap sit, and since the U-shaped dies apply pressure to the free edges of flap '55 and across the hinge line 52 it will be apparent that after filling of the container, the flap Eli may be readily sealed along its periphery and along the hinge line to prevent leakage from the container, this being accomplished without disturbing the closure of the dispensing opening, which has already been effected by the portion 53 of flap M as described.

In the event the coating material is paraffin or some other low melting point material, and in the event an adhesive of the heat-sealing type is employed in adhesively securing the flap 5 to the flap ill to effect a final closure, it is desirable to localize the application of heat to the flap 54 during the heat sealing operation in order to prevent the coating from melting and dropping into the container. Due to the employment of the U-shaped heated die ll, which engages only the peripheral portion of the flap 5d, the heat is localized and melting of the coating is substantially eliminated.

As heretofore stated, it may sometimes be found desirable to form and coat the container, and thereafter seal it temporarily to permit shipment empty to another location for filling and subsequent rescaling, the interior of the empty container being protected against contamination during shipment so as to avoid the need for sterilizing prior to filling. The present container is well adapted to this type of operation, the con tanier in the form shown in Fig. at having its interior coated with wax or other suitable protective material through the opening id, and the exterior preferably being similarly coated by the operation of dipping the container in the bath of coating material. Assuming that wax is used as the coating material, the coating is set by cooling in a suitable refrigerator, resulting in a container coated with wax, and including a coating of wax over the adhesive band 58 on closure flap E4. The wax normally used for such coatings has a lower melting point than the adhesive 58, thus permitting softening of the wax coating for heat sealing at a temperature below that required to activate the adhesive 53 for heat sealing, and so low as to leave the adhesive 53 sub stantially unaffected. The temporary closure may be affected in substantially the same manner as the final closure heretofore described, tie upper portion of the container being placed between dies of a machine of the type shown in Fig. 7 with the flap 55 folded down against the flap 4G. The heater 18 is so chosen or adjusted as to heat the die ll sufficiently to soften the wax coating over the adhesive 58 and on the upper surface of flap l0 sufiiciently to soften or render the wax coating tacky without disturbing the adhesive coating 53, th parts being pressed together by the operation of the dies during or after the soitening operation to effect a temporary bond between, which, in the event the protective coating is of wax or other suitable material, is strong enough to maintain and seal the flap 54 in closed position, but is not strong enough to damage the container during subseqr 11' opening of the closure flap. In the event it is found necessary to cool the wax coating to insure a good bond, this may be accomplished by cooling the dies while maintaining pressure on the flaps, or by removing the container to other similar machine having dies maintained at a proper temperature to rapidly cool the wax while holding the parts in engagemen The container is now ready for shipment erupt; to a filling station, where the container can be reopened for filling by lifting the flap 54 and breaking the relatively weak bond between the flap 54 and flap 43. Subsequent to the filling operation, the container is placed in a machi of the type shown in Fig. 7 having dies maintained at a temperature suitable for activating the adhesive 58, and the final closure made by heat and pressure as previously described. In order to facilitate reopening the flap 54 and may; be: provided at the; upper-edge: of, panel .26.;

and acorresponding cut-out as on the edgeof.

flaptdfi, as shown in Fig. 1.- When. the top is formed and sealed, these cut-outs are substantially in register so as to expose a portion 85 of the outer edge of flap 54, thus permitting the. latter to be grasped or acted on bya suitable tool..- to break the wax'sealand lift'the fiap to permit.

filling of the container.

From the foregoing, it will be seen thatthe present invention provides a novel blank and containerv structure which maybe readily formed in a single piece from paperboard or other sir lar sheet material. Furthermore, it will. be-apparent thatas shown inthe drawings, and par-- ticularly in Fig. 6, a finished containeris formed havinga top closure which. presents a substane tially flat and unbroken or non-recessed outer surface having distinctive advantages from a sanitation standpoint when used for the packaging of food products such as milk, for example.

It will also be noted that the closure member presenting this fiatunbrcken outer surface in. cludes not only a tab separable therefrom to providea dispensing opening, but also a. separate flap which, prior to closing, isadapted to provide. access to a filling opening for the container which is. entirely separate and distinct from the dispensing opening. A protected dispensing open ing is provided which may be sealed prior. to fill.- ing, of the container, and which remains undisturbed during the subsequent filling operation...

The construction is such that the container may be substantially completely assembled in one room and ,filledin another room, the. only opera tions performed in. the filling room. being those of filling,.c1osing the filler flap, and sealing the latter; thus greatly minimizing the possibility of contaminating the product with which the container is filled. The container. is also readily adapted for temporary sealing, and subsequent opening, filling, and rescaling, a procedure which is'oftenhighly desirable.

While one form of the container has been shown, and described herein with considerable particularity, it wil1 be understood by those skilled in the art, that various modifications may be resorted to without departing from the spirit of the invention. For example, in some instances the flap ill may-be dispensed with entirelyjif desired, in which case the portions 53 and 54 of closure flap ii may be adhcsively secured to the flat end of the container formed by the flange forming panels 26, 2?, 3i and 32, rather than to. the fiat end formed by securing theflapddto.

1. A'closure for the open end of a tubular con-i tainer of rectangular cross section including a closure flap adhesively secured to an end portion of the container and closing substantial1yonehalf of the open end thereof, said flap presenting a flat unbroken outer surface, and a rectangular filler flap integral with and hingedly connected to the first named flap along one edge and having its remaining edges free to allow independent pivotal movement thereof aboutsaid hingedcom nection to expose the remaining portion ofthe openiend of; the container to allow filling; of; the

10. container;theefreeeedgcgofsaid filler flapbeing, adapted e-adhesively:securedtqthe end. por.-.- tionof:thecontainer to. close said remainingpore tion" of said;,op en: end and. presenting ,afiat and;v

, unbroken i outer surface -,forming a, continuation.

\ the upper end, of said..container, a substantially rectangular closuretfiap. integralwithone'of 'said flange .forming panels. providedrwitha dispensing, and filling openingand adhesively; secured to saidi flange,- and. a....second, substantially, rectangular closurea fiap 'scored .alonggthe median. line. therof from 1 one; side-.2 edge to. .theothento provide, sep: arateportions ,hingedly connected together, along saidanedianli-ne, oneportion-being integral with the fiangeformins-panel.Opposite said onefiange forming; panel and adhesively secured. to said first named closure. flap and having. atear strip covering the. dispensmgpart ofsalol opening, and the other. portion having three; i'reeedges. adapted to, be. ao'hesively. securedto ,said firstnamedroiozsure..-fiap .to,-=close; the filling; part of .said. opening after the containenhas. been ii1led ,throug h said. fiilmg part oiathe: opening,

3. A, tubularp container. of rectangular cross. sectionhaving side wall ;panels,,a bottom closure,.

, an outwardly extendingmarg nal,flange forine about. the upper. ends; of said; side wall panels, a first rectangularclosure. flap, integral with and hingedly conneetedsto aportion, of saidilange and adhesively secured.tosaidmarginal flange. and. provided with a port,;,a. second, rectangular clo: sure fiap integral Wlthand. hingedly connected. with: another. portion-coi said. flange .and hesively; secured; to.said; first.nap and covering portion orjsaid port saiohsecond.closure flap pro. video. with. a ,tear. strip.separableqtherefrom provide. agdispensing opening therein register g l with .said...port por.ti0n,.:v andia. .third. rectangular. flap, integral wltnwand. hingedly connectedtosaid second; nap at; one? edgeand having three side; edges-,r said ;tnira;;rlap being adapted. to, be aohesiveiy securedsto .saio firstirlap t0. cover...the. remainlng portion.of; saidrportaiter the con.- tamer has, beenfilled.

4... A. tubular papers. container. of. rectangular. crosssectionhaving aznl ralitya i i wall panels;

nCl'.1t1'leIB0I,,.8;nd;ac pair; 0 rectangular 11011153103 ing, flaps; .OIIELLOf; whichiises'ecurely; bonded ,to aid, flange and sisipromdednwrthran;opening QlUT/liil g3, dispensing... and...fillmgaportions; and the other. of whichi includes;two .i-hingedl ;com1ected parts,

dispensing portion nftheppening to dispensethe.

container, contents.

5. In a paperboard container of rectangular cross section having, side walls. and'an outwardly .extendingmarginal flange atthe upper end: of

said side walls, means providing a sealed end closure for said upper end having a substantially flat and unbroken outer surface lying in a plane substantially at right angles to the vertical axis of the container, said means including a flat one piece closure member extending to the extreme edges of said flange and scored substantially along the median line thereof from one side edge to the other to provide a pair of hingedly connected flaps integral with each other and adapted to be separately sealed against said upper end to close the upper end of said container, one of said flaps being provided with a tongue separable therefrom along lines of weakness to provide a dispensing opening and the other flap serving prior to closing and sealing thereof to provide a filling opening separate and distinct from said dispensing opening.

6. A tubular container having side wall panels, a bottom closure, an outwardly extending flange formed about the upper ends of said side wall panels having a cut-out portion along one edge, a first closure flap having an opening therein, said closure flap being adhesively secured to said flange and provided with a cut-out portion-substantially registering with the cut-out portion of said flange, a second closure flap provided with a tear strip separable therefrom to provide a dispensing port therein and adhesively secured to said first flap covering a portion thereof and also covering a portion of said opening, and a third flap integral with and hingedly connected to said second flap and separately closed and releasably sealed to said first flap and covering the remaining portion thereof and also covering the remaining portion of said opening, said third flap being so dimensioned along one of the free edges thereof as to overlie the cut-out portions of said flange and ported flap, whereby said free edge may be grasped to break said seal and move said third flap to open position.

7. A blank for a tubular container of rectangular cross section, comprising a sheet of paperboard material scored and cut to provide side Wall panels, bottom closing flaps at one end of said side wall panels and a flange panel at the other end of each of said side wall panels, a substantially rectangular top closing flap formed integrally with oneof said flange panels and being substantially coextensive with the length of the latter, said top flap having a centrally positioned opening therein providing filling and dispensing portions, a second substantially rectangular top flap scored substantially along the median line thereof from one edge to the other to provide a pair of substantially rectangular hingedly connected portions, one of said portions being formed'integrally with a second flange panel and the (ther portion being free of said second flange panel, said scored median line extending at right angles with respect to the length of said second flange panel and the combined dimensions of said'portions taken parallel with the length of said second flange panel being substantially equal to the length of said second flange panel, said one portion being weakened along lines defining a tear strip intermediate two side edges therecf, and the dimension of said opening in the first named top flap in a direction parallel with the length of its integrally connected flange panel being greater than the corresponding dimension of either of said portions.

8. A flat blank for a tubular container of rectangular cross section, comprising a sheet of paperboard material scored and out to provide side wall panels, bottom closing flaps at one end of said side wall panels, and a plurality of flange panels at the other end of said side wall panels, the flange panels forming outwardly extending marginal flanges when the blank is folded into a container, a substantially rectangular top closing flap formed integrally with one of said flange panels and having a centrally positioned opening therein providing dispensing and filling portions and having also a surface over which the contents of the container, when the container is assembled, may be poured, a second substantially rectangular top flap scored along a median line from one edge to the other to provide a pair of hingedly connected parts of similar shape and area, one part being integrally connected with a second flange panel and said scored median line extending at right angles to said second flange panel, and the combined dimensions of said parts taken parallel with the length of said second flange panel being substantially equal to the length of the latter, said one part having a tear strip provided with a lift tab extending beyond the margin of said one part, the tear strip, when the container is assembled, overlying the dispensing portion of said opening and said surface, the other part being free of said second flange panel and allowing filling of the container when assembled, through the filling portion of said opening, and the dimension of said opening in a direction parallel with the length of its integrally connected flange panel being greater than the corresponding dimension of either of said hingedly connected parts of said second top flap.

9. A closure for a rectangular tubular container of the type having an opening at one end thereof, said closure including a rectangular flap adheslvely secured to said end of the container to partially close said opening and provided with a tear strip between opposite side edges of the flap and separable from said flap to rovide a dispensing opening therein registering with a portion of the first named opening, and a second rectangular flap integral with and hingedly connected With the first named flap and provided with three free edges so that the second flap is movable to open and closed positions about the hinged connection to open and close the remaining portion of the first named opening, said second flap when open, forming a shield between said remaining'portion and the outer surface of the first named fiap and adjacent areas when filling the container through said remaining portion and adapted to be adhesively secured to the end of the container after filling thereof to close the remaining portion of said first named opening.

ROY S. SANFORD.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,128,893 Bergstein Sept. 6, 1923 2,249,052 Seifert July 15, 1941 2,272,203 Hothersall Feb. 10, 19 .2 2,321,042 Preis June 8, 1943 2,321,059 Seymer June 8, 1343 2,335,855 Lanigan et a1. Dec. '1 1943 2,339,896 Waters Jan. 25: 19 .4 2,349,743 Otto May 23, 1944 ,360,415 Gilbert Oct. 17 19% 2,415,081 Brooks Feb. 4. 19 17 2,581,237 Casler Jan. 1, 1952 2,593,019 Glaser Apr. 15, 1952

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